This study investigated the mood responses and oxyhemoglobin saturation after 45 minutes of exercise at VT-I intensity in a hypoxia-simulated environment in healthy males (N = 10). Ss performed a protocol of rectangular load for 45 minutes at sea-level and in a normobaric chamber simulating an altitude of 4,500 m. Mood responses induced by exercise (Mood Scale of Visual Analogues – VAMS) and oxyhemoglobin saturation were measured at different time-courses: before, immediately after, and 30 and 60 minutes after the finish of the protocol.

A comparison between the two conditions showed no differences. However, in the simulated hypoxia, the Sedation Physics and Other Feelings and Attitudes dimensions exhibited a reduction immediately after exercise when compared with baseline, indicating negative symptoms of mood. At the same time, a decrease of the oxyhemoglobin saturation when compared with the baseline condition was observed. That condition ameliorated 60 minutes after the finish of the exercise protocol in the hypoxic group. The control group showed no change in this variable.

Implication. Physical exercise at an altitude of 4,500 m promoted negative mood symptoms accompanied by a reduction in oxyhemoglobin saturation.